There are several, methods available to inspect the interior of tubes for detecting any obstruction inside. One of these methods relies on acoustic detection for detecting the presence of a blockage in a pipe. In essence, an acoustic transmitter is used to generate an acoustic signal that propagates through the liquid-filled pipe and a transmitter that receives the signal and/or any signal reflection. Data processing means are provided for analyzing and interpreting the signal to determine if a blockage exists in the pipe and its size and location inside the tube. However, there is a constant problem associated with this technology in terms of acoustic signal reflection since tubes or pipes might have different sizes, materials and are subjected to conditions creating a situation where some of the acoustic signal radiates through the tube affecting the analysis and interpretation of the received signal.
Thus, what is needed is a cost-effective tube arrangement that reduces or eliminates the amount of acoustic energy that radiates through the tube.